GRAPH <http://abstracts.agu.org/graphs/1.0/static> {
  <http://abstracts.agu.org/graphs/1.0> void:subset ?g1 .
  <http://abstracts.agu.org/graphs/1.0> void:subset ?g2 .
  <http://abstracts.agu.org/graphs/1.0> void:subset ?g3 .
}